2-quinoxaline pseudoureas



United States Patent 6 Claims. 0. 260-250) ABSTRACT OF THE DISCLOSURE The invention concerns 1-phenyl-3-din1ethylpseudoureas substituted in the 2 position by various heterocyclic substituents including quinoxaline. The compounds are useful as herbicides.

This application is a division of application S.N. 299,174 filed Aug. 1, 1963, now US. Patent 3,260,726.

The present invention is concerned with hitherto unknown isothiourea derivatives, which have herbicidal properties, as well as with a process for their production.

It is an object of the present invention to make available new isothiourea derivatives. A further object consists in the enrichment of the herbicidal active materials with further herbicidal active materials, some of which also have selective properties. Finally, an object of the invention is to be seen in the indication of a process for the production of these new isothioureas. Further objects can be seen from the following description and the examples.

It has been found that isothiourea derivatives of the general formula N N R. 20-8-03) Ar-N in which R and R individually stand for possibly substituted alkyl radicals, R and R together with the N-atom, jointly stand for possibly substituted heterocyclic radicals, Ar stands for possibly substituted aryl radicals, and A, together with the group, stands for a possibly substituted heterocyclic radical with 1-3 rings which, however, is not substituted in the lat-position to C by the radical:

show strong herbicidal properties.

' 3,415,828 Patented Dec. 10, 1968 Furthermore, it has been found that isothiourea derivatives of the Formula I are obtained when aryliminocarbonic acid amide halides of the formula:

N Ra C-Hal Ar-N (III) in which R R and Ar have the same meaning as given above and Hal stands for halogen,

are reacted with cyclic thioamides of the formula:

N HSO A in which A, together with the group, has the same meaning as given above,

possibly in the presence of an acid-binding agent and possibly in the simultaneous presence of a solvent.

The cyclic thioamides are given in the Formula IV in the enthiel form. The enthiol form is in equilibrium with the thiono form corresponding to the following formula:

The arylimino-carbonic acid amide halides are clearly characterised by the Formula III. In this formula, R and R preferably stand for alkyl With 1-5 carbon atoms, possibly substituted by halogen and/ or alkoxy with 14 car bon atoms. R and R together with the nitrogen atom, preferably stand for heterocyclic radicals which 5-6 ring members and are possibly substituted by halogen and/or alkoxy with 1-4 carbon atoms. Ar preferably stands for the phenyl or naphthyl radical. These radicals may be substituted by alkyl radicals with l-4 carbon atoms, halogen and/or alkoxy with l-4 carbon atoms.

As examples of arylimino-carbonic acid amide halides, there may be mentioned: phenylimino-carbonic acid dimethylarnide chloride, phenylimino-canbonic acid diethylamide bromide, phenylimino-carbonic acid bis (2-methoXy-ethyD-amide chloride, chlorophenylimino-carbonic acid dimethylarnide chloride, dichlorophenylimino-carbonic acid dimethyl-amide chloride, phenylimino-carbonic acid morpholide bromide, phenylimino-carbonic acid piperide chloride, as well as chlorophenylimino-carbonic acid pyrrolidine chloride, 4-methyl-phenylimino-carbonic acid dimethylamide chloride and 4-methoXy-phenyliminocarbonic acid dimethyl-amide chloride.

The cyclic thioamides used for the process according to the invention are clearly characterised by the above Formula IV. Therein, A, together with the group, preferably stands for a heterocyclic radical with l-3 rings, whereby all rings or only one or two rings may be of heterocyclic nature. The remaining rings can be of aromatic or cycloaliphatic nature. The individual ring systems preferably have 6 ring members. These heterocyclic radicals can be substituted by radicals of the Forrnula II, haloalkyl with 1-2 carbon atoms, nitro, aryl, such as phenyl, alkyl with 1-4 carbon atoms, alkoxy or akylmercapto with l4 carbon atoms, the amino group, alkylamino and dialkylamino with 1-4 carbon atoms, canboxylic acid ester, carboxylic acid amide groups and/ or halogen.

As heterocyclic thioamides which, according to the invention, are able to yield S-heterocyclically substituted isothioureas with the arylimino-carbonic acid amide halides, in detail, the following groups of compounds may be mentioned: Z-mercapto-pyridines, 2-mercapto-quinolines, mercapto-inidazoles and -imidazolines, mercaptopyrimidines, e.g., thiouracils and thiobarbituric acids, mercapto-pyrazines, thiohydantoins, rhodanines, mercaptol,2,4-triazoles, mercapto-thiazoles and -oxazoles, mercapto-thiazolines and -oxazolines, mercapto-1,3,4-thiadiazoles and -oxidazoles, mercapto-1,2,4- and -l,3,5-triazines, e.g. 2-rnercapto-4,6-diamino-triazine-(1,3,5), 2- mercapto- 4-ethy1amino-6-chloro-triazine-( 1,3,5 mercapto-quinazolines, monomercapto-quinoxalines, mercapto-phthalazines, mercapto-benzimidazoles, mercaptobenzoxazoles, mercapto-benzthiazoles, mercapto-indazoles, thiouric acids and other mercapto purines.

The reaction according to the invention can be carried out in the presence of solvents. For this purpose, there are suitable: inert organic solvents, such as hydrocarbons, for example benzene; chlorinated hydrocarbons, for example chlorobenzone; ethers, for example dioxan; ketone, for example acetone, and also esters. It is moreover, also possible to work in the presence of water.

For the neutralisation of the hydrogen halide formed in the reaction according to the invention, there are used the usual acid-binding agents, such as tertiary bases, for example pyridine, N,N-dimethyl-aniline, alkali metal carbonates, such as sodium carbonate and potassium carbonate; alkali metal hydroxides such as sodium and potassium hydroxide. However, the alkali metal salts of the mercapto compounds can also be used instead of the free mercapto compounds.

The reaction according to the invention can be carried out in a wide temperature range. It is expedient to work between l0 and +100 C., preferably in the range of 0 to 50 C.

The reaction of the arylimino-carbonic acid amide halides with the cyclic thioamides preferably takes place in solution or suspension with the addition of acid-binding agents. This reaction may be carried out, for example, in such a manner that the reaction components are allowed to act upon one another in an organic diluent in the presence of a tertiary amine. According to another method of procedure, the metal salts of the thioamides are reacted in solution or suspension with the arylimino-carbonic acid amide halides. According to the simplest and, in most cases, satisfactorily proceeding process, solutions of the cyclic thioamides are mixed, in the presence of at least molecular amounts of a strong inorganic base, possibly after dilution with a water-miscible solvent, with molecular amounts of the arylimino-carbonic acid amide halide. In the presence of water, the reactions must be carried out with careful cooling in order to avoid saponification of the arylimino-carbonic acid amide halides.

Working up of the reaction mixtures obtainable according to the invention takes place according to known methods. It is, for example, possible to proceed in such a manner that the reaction mixture is poured into water, the separated product taken up in an organic solvent and the solvent subsequently distilled off.

The compounds according to the invention influence the growth of plants and can, therefore, be used as weed destroying agents. By weeds there is to be understood, in the widest sense, all plants which grow in places where they are not desired. Whether the compounds according to the invention act as total or selective herbicides depends, in the main, upon the amount used.

The compounds according to the invention can be used in the case of the following plants for example: dicotyledons, such as mustard (Sinapis), cress (Lepidium), milkweed (Galium), chickweed (Stellaria), camomile (Matricaria), French weed (Galinsoga), gooses foot (Chenopodium), stinging nettle (Urtica), old mans beard (Senecio), cotton (Gossypium), beet (Beta), carrots (Daucus), beans (Phaseolus), potatoes (Solanum), coffee (Coffea); monocotyledons, such as timothy grass (Phleum), panicle grass Poa), fescue grass (Festuca), eleusine (Eleusine), bristle grass (Setaria), ray grass (Loli um), brome grass (Bromus), hen millet (Echinochloa), maize (Zea), rice (Oryza), oats (Avena), barley (Hordeum), wheat (Triticum), millet (Panicum) and sugar cane (Saccharum).

In this list, the given types of plants are to be understood as representative examples for the species indicated in latin. The use of the compounds according to the invention is, neverthless, in no way limited to these species but extends, in the same manner, also to other plants.

The compounds according to the invention can be used as such or in the form of the usual formulations, such as emulsifiable concentrates, spray powders, pastes, soluble powders, dusting agents and granulates. These are produced in known manner (cf. Agricultural Chemicals, March 1960, pp. 35-38). As auxiliaries the following are mainly to be used: solvents, such as aromatics (e.g. xylene, benzene), chlorinated aromatics (e.g. chlorobenzenes), paraffins (e.g. mineral oil fractions), alcohols (e.g. methanol, butanol), amines (e.g. ethanolamine, dimethyl formamide), and water; carrier materials, such as natural rock powders (e.g. kaolin, clay, talc, chalk) and synthetic rock powders (e.g. highly dispersed silicic acid, silicates); emulsifying agents, such as non-ionic and anionic emulsifiers (e.g. polyoxyethylene-fatty acid esters, polyoxyethylenefatty alcohols ethers, alkyl sulphates and aryl sulphonates); and dispersing agents, such as lignin, sulphite waste liquors and .methyl cellulose.

The active materials according to the invention can be present in the formulations in admixture with other known active materials.

The formulations contain, in general, between 0.1 and percent by weight of active material, preferably between 0.5 and 90.

The compounds obtainable according to the invention or their preparations are used in customary manner, for example, by pouring, spraying, scattering or dusting.

Example A.Post-emergence test Solvent: 10 parts by weight of acetone. Emulsifier: 5 parts by weight of 'benzyl diphenylhydroxypolyoxyethylene ether.

For the production of a suitable active material preparation, 1 part by weight of active material is mixed with the stated amount of solvent, the stated amount of emulsifier added thereto, and the concentrate subsequently diluted with water to the desired concentration.

Test plants which have a height of about 5-15 cm. are sprayed with the active material preparation until just dew wet. After three weeks, the degree of damage of the plants is determined and assessed with the characteris ing numbers 0-5 which have the following meansing.

: no effect single light burnt spots clear leaf damage single leaves and stem parts partially destroyed plants partially destroyed plants completely destroyed 5 6 Active materials, active material concentrations and chloride. The reaction product precipitated with water is results can be seen from the following table: taken up in benzene the benzene solution dried over 3 TABLE.POST-EMERGENOE TEST Active mate- No. Active material rital toncen- Mustard Oats Beet Cotton Wheat Millet Tomatoes Beans re. 1011 11]. percent (1) Compound according to 0. 4 5 5 5 2 3 6 3 3 Example 5, first formula. (2) Compound according to 0. 4 4'5 4-5 5 4 3 5 5 5 Example 5, second formula. (3) Compound according to 0. 4 0 0 1 5 1 2 Example 6. (4) Compound according to 0. 4 5 4 5 2 2 5 2 4-5 Example 12a.

Example B.Pre-emergence test 1? sodium sulphate and evaporated in a vacuum. As residue Solvent: parts by Weight of acetone there remam 18 of the Compound: Emulsifier: 5 parts by weight of benzyl diphenylhdroxypolyoxyethylene ether For the production of a suitable active material prep- 20 SC/ aration, 1 part 'by weight of active material is mixed N \NwHm with the stated amount of solvent, the stated amount of in the form of a viscous dark brown on emulsifier added thereto and the concentrate diluted with water to the desired concentration Calc.: N, 18.17%; S, 10.40%. Found: N, 17.85;

Seeds of the test plants are sown in normal soil and, h b after 24 hours, the active material preparation is poured n a correspon t t e w, etween i" thereon. The amount of Water per unit surface area is m?thy.l'2'mercap.toqumolialme and p h i q 10 thereby expedienfly kept constant The active material aclddimethylamide chloride also provides an oily reaction concentration in the preparation is of no importance; product W for punfiqanonflls dlssolved m carbon only the amount of active material applied per unit surtetrachlonde and treated Wlth actlve charcoal face area is decisive. After three weeks, the degree of CH damage to the test plants is determined and assessed with 3 the characterising numbers 0-5 which have the following S C% meaning: N 0 no effect 3)2i l: slight damage or delay of growth Cale: N, 17.38; S, 9.95%. Found: N, 16.80; S, 9.60%. 2: distinct damage or growth inhibition E l 2 3: considerable damage and only deficient development,

or only 50% germination 21.4 g. of the sodium salt of 2-methoxy-3-mercapto- 40 quinoxaline are suspended in 150 ml. of acetone. 18.2 g. g gf g fifi g g after germmanon or only of phenylimino-carbonic acid dimethylamide chloride are added dropwise at room temperature The mixture is then lants c m letel destro ed or no er in no 5 p o p y y g m a stirred for a further hour at room temperature, the solu- Active materials, active material concentrations and tion of 2 g. of sodium hydroxide in ml. of water added results can be seen from the following table: 45 thereto and further stirred for one hour at room tempera- TABLE.-PRE-EMERGENCE TEST Active No. Active material material Mustard Oats Beet Cotton Wheat Millet Tomatoes Beans employed in kg./ha. (1) Compound according to 40 5 4 3 0 4 3 Example 5 first formula. (2) Compound according to 40 5 4-5 5 1 1 4. 5

Example 5 second formula. (3) Compound according to 40 5 1 1 0 3 0 Example 6.

15.1 g. of 2-mercapto-benzoxazole are dissolved in a ture. Upon the addition of water, crystals separate out, Solutlon 0f of SQdIHm hydfoxlde In 40 IIIL 0f Which are filtered off with suction, dried and recrystallised and, after dilution with 150 ml. of acetone reacted as in f o benzelm Example 1 with 18.2 g. of phenylimino-carbonic acid dimethyl-amide chloride. The product precipitated With water at the end of the reaction is filtered off with suction and recrystallized from ethyl acetate. Yield 19 OCH3 Yield: 15 g. of a compound of the formula g. of a compound of the formula (M.P. '1a0 1a2 c. N HM (M.P. 185188 o. Example 3 Example 1 20.5 g. of 2-ethylamino-3-mercapto-equinoxaline are 16.2 g. of Z-mercapto-quinoxaline are dissolved in an reacted: as E p e 1, with 18.2 g. of phenyliminoaqueous acetonic sodium hydroxide solution and reacted carbonic acid dlmethylamlde chloride in the presence of with 18.2 g. of phenylimino-carbonic acid dimethylamide aqueous sodium hydroxide solution. The working up yields 20 g. of a non-crystallising, viscous, yellow oil With the constitution:

Calc.: N, 19.92%; S, 9.12%. Found: N, 19.37%; S, 8.80%.

Example 4 16.2 g. of 4-mercapto-quinazoline are reacted, as in Example 1, with 18.2 g. of phenylimino-carbonic acid dimethylamide chloride with the addition of the calculated amount of aqueous sodium hydroxide solution. The reaction product is recrystallised from alcohol.

Yield: 18 g.

Example 5 7.2 g. of 3,6-dimercapto-pyridazine are dissolved in a solution of 4 g. of sodium hydroxide in 40 ml. of water and, after dilution with 150 m1. of acetone as in Example 1, reacted with 18.2 g. of phenylimino-carbonic acid dimethylamide chloride. Working up is carried out as in Example 9. There are obtained 13 g. of a viscous oil with the constitution:

Calc.: N, 19.2%; S, 14.68%. Found: N, 19.95%; S, 14.30%.

Example 6 14.75 g. of 2-chloro-3-mercapto-quinoxaline are dissolved in a solution of 3 g. of sodium hydroxide in 50 ml. of water. After dilution with 100 ml. of acetone, 13.7 g. of phenylimino-carbonic acid dimethylamide chloride are added dropwise, with cooling, at a temperature between 5 and 10 C. The mixture is further stirred for a /2 hour with cooling and for 1 hour at room temperature, 250 ml.

of Water are added, and the separated product is filtered off with suction. It is washed with water and dried. Yield: 23 g. of a compound of the formula:

M.P. 230232 C. (Alcohol) from 2,6-dimercapto-4-methyl-pyrimidine a compound of the formula:

e 9 C- s s C\ (CH3) N N (0 Hz!) 2 We claim:

1. A compound of the formula 5. The compound of claim 1 wherein R is chloro. 6. A compound of the formula References Cited Sasse et al. (Abst. Belgium 612,972, July 1962) Chem. Abst. vol. 58, column 1475 (1963).

Wolf c. al. Jour. Amer. Chem. Soc., vol. 76, p. 2266 (1954).

HENRY R. JILES, Primary Examiner.

N. TROUSOF, Assistant Examiner. 

